Involvement of Endogenous Vasopressin in High Plasma Osmolality-Induced Anorexia via V1 Receptor-Mediated Mechanism

Ryota IKEMURA, Takashi MATSUWAKI, Keitaro YAMANOUCHI, Masugi NISHIHARA
2004 Journal of Veterinary Medical Science  
It is known that water deprivation or injection of hypertonic saline induces anorexia. The present study examined the possible involvement of vasopressin in the suppression of food intake during high plasma osmolality. Intraperitoneal injection of vasopr essin (20 µg/kg) into male rats significantly suppressed food intake for 1 hr. This anorectic effect of vasopressin was reversed by simultaneous injection of a peptide antagonist for V 1 receptor (40 µg/kg), but not for V 2 receptor (40 µg/kg).
more » ... eceptor (40 µg/kg). Intraperitoneal injection of hypertonic saline (20% NaCl, 2 ml/kg) similarly suppressed food intake for 2 hr, which was associated with a transient increase in plasma vasopressin concentrations. This hypertonic saline-induced suppression of food intake was blocked by a V 1 receptor antagonist. Vasopressin (40 ng/2 µl) directly administered into the third ventricle of the brain also suppressed food intake for 1 hr. These results suggest that vasopressin participates in the suppression of food intake during high plasma osmolality, the action of which is mediated by V 1 receptors in the brain. KEY WORDS: food intake, plasma osmolality, vasopressin, V 1 receptor.
doi:10.1292/jvms.66.951 pmid:15353846 fatcat:rwnbk2n6jzcxvlembyw342qbg4